Canadian Geographic Education
geographic engagement
among Canadians

Follow us on Twitter!

Follow us on Twitter!


To demonstrate how rain affects topsoil.


  • Dirt
  • Red powdered tempera paint
  • Measuring spoon, teaspoon (5 ml)
  • Funnel
  • Coffee filter paper
  • Wide mouthed jar, 1 qt. (1 liter)
  • Measuring cup, 1 cup (250 ml)
  • Stirring spoon
  • Procedure

  • Add 1¼ teaspoon (1.25 ml) of red tempera paint to 114 cup (75 ml) of dirt. Mix thoroughly.
  • Set the funnel in the jar.
  • Place the coffee filter inside the funnel.
  • Pour the colored sand into the paper filter.
  • Add 1¼ (75 ml) of water to the funnel.
  • Observe the water dripping into the jar.
  • Pour this water out of the jar and add another 1¼ cup (75 ml) of water to the funnel.
  • Results
    The liquid dripping out of the funnel is red.

    The red paint represents nutrients in topsoil that are soluble in water. Nutrients dissolve in rainwater and feed the plants growing in the soil. If the rain is too heavy, the water runs across the land, taking the dissolved nutrients with it. Excessive rains can leave the topsoil lacking in necessary nutrients.

    Printed with permission from Michal L. Le Vasseur, 2001

    Adobe PDF download Runoff (Adobe PDF document)


    Share this page

    Did you know that a 2005 National Survey determined that one-third of adult Canadians can be considered “geographically illiterate”?

    Top 10 reasons to study geography…

    Find out now!
    “Geography is the lens for the soul of the earth. With the knowledge of geography, one can examine the earth’s past, assess the present and predict future situations. You can literally be ‘lost’ without geography!”

    National Geographic Education Foundation

    Donate to the Royal Canadian Geographical Society

    © 2016 Canadian Geographic Education SITEMAP  |   CONTACT  |   PRIVACY POLICY  |   FRANÇAIS